House fully insulated with 2″ rigid foam
I have been an avid viewer of this site for a couple of years now, ever since I knew I was going to be building my new home. This is, however, my first post to the site.
I know that I am going to be asking questions that already have answers out there in other blogs on this site, but you all know that not every situation is the same so I would really like direct feedback on my exact situation so that I don’t miss anything. I am an extreme DIY’er that insists on doing something right the first time so that it lasts for decades, and I am always looking to do something new, especially if it can help my house be more efficient or ‘green’. I will have a general contractor for my house but I do plan to do a lot of work myself. My GC is on board for trying something new!
My questions today are all about exterior insulation, specifically about rigid foam.
I numbered each line so that maybe it would help you comment on specific areas of my plan.
First, a little about my situation:
1. My house will be built on about 6 acres in Northwest Ohio, so I have to worry about the cold and the hot (humidity). Climate zone 5 I believe.
2. My house will be about 2400 sqft. It will be a 2 story house with a full unfinished, walkout basement.
Here is my plan of attack. Please comment.
3. Poured concrete footers will be either sprayed with flexible moisture barrier or covered with plastic. This will stop moisture from seeping up through the footer into the walls.
4. 8″ concrete walls will be sprayed with flexible moisture barrier.
5. Walls will be 2×4 construction, 16” OC
6. I plan to cover the exterior with ½” OSB sheathing and plan it so that it ends flush with the outside of the foundation walls.
7. Wrap this sheathing with house wrap vapor barrier.
8. Use 2” of polyiso to cover all of the walls. It will be a continuous run of rigid foam from 2×4 walls down to the footer. Sealing all joints.
9. Install 1×4 latts 16” OC over top of the foam to act as nailers for the siding. Bottom part of the walls and foundation walls will be covered with stone veneer using a metal lathe and scratch coat. Between the siding and the stone there will be a drip edge and bug screen.
10. For the interior, I plan to install unfaced batt insulation in the 2×4 wall cavities.
1. How do I manage the transition from the wall to the roof/ceiling?
2. Best way to insulate attic/cathedral ceilings?
3. Should I worry about the siding warping or not laying straight when just being nailed to latts, vs sheathing?
Any advice will be much appreciated. Thanks for everyone’s help in advance!
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